PET Imaging Study Using Evuzamitide to Detect Cardiac Amyloidosis in Patients With Inconclusive Nuclear Scans and Elevated TAD1 Levels

The goal of this study is to learn whether PET-CT imaging using evuzamitide can help diagnose transthyretin cardiac amyloidosis (ATTR-CA) in patients whose standard nuclear imaging results are unclear but who have elevated TAD1 levels in their blood. The main question it aims to answer is: Can evuzamitide PET-CT imaging detect signs of cardiac amyloidosis in patients with non-diagnostic nuclear scintigraphy but elevated TAD1 levels? Participants who meet eligibility criteria will receive a single PET-CT scan with evuzamitide and will be followed for approximately 28 days to monitor safety and collect additional clinical information.

Inclusion Criteria: 1. Diagnosed as having heart failure or TTR variant allele carriers without symptoms of heart failure. 2. Non-diagnostic nuclear scintigraphy for ATTR-CA (Perugini Grade 0 or 1). 3. Elevated levels of Transthyretin Amyloid Detector-1 (TAD1). 4. No evidence of monoclonal proteins by assessment of serum kappa and lambda free light chain ratio and immunofixation of serum and urine. 5. Must have given written informed consent (signed and dated) and any authorizations required by local law and be able to comply with all study requirements. 6. Able to understand and sign the informed consent document after the nature of the study has been fully explained. Exclusion Criteria: 1. Primary amyloidosis (AL) or secondary amyloidosis (AA). 2. Ventricular assist device. 3. Disabling dementia or other mental or behavioral disease. 4. Enrollment in a clinical trial not approved for co-enrollment. 5. Continuous intravenous inotropic therapy. 6. Inability or unwillingness to comply with the study requirements. 7. Chronic kidney disease requiring hemodialysis or peritoneal dialysis. 8. Patients taking heparin, or heparin derivatives (e.g. low molecular weight heparins) for anticoagulation. 9. Other reason that would make the subject inappropriate for entry into this study. 10. Pregnancy or current lactational feeding of infants.